1.0 Field of the Invention
The invention relates generally to a device for metering a pasty product and mixing the same with a solvent, and more specifically so such a device having an exchangeable storage container which is arranged in a dimensionally stable vessel and holds the pasty product, and having a metering arrangement which is arranged beneath the vessel and performs a feeding action by means of negative pressure.
2.0 Discussion of Related Art
Liquid to pasty detergents are known. These detergents are generally used for to domestic requirements, which means that they are to be sufficiently free-flowing and can be easily poured out and metered. Since, moreover, they are intended to be stable under storage conditions within a relatively large temperature range, it is typically necessary to use organic solvents and/or hydrotopic additives. However, these additives do not have any washing action, are comparatively costly, and take up additional packaging volume as well as additional transporting and storage capacity. Also problematic, in particular, is use of inflammable solvents which, on account of the comparatively high throughput of detergents in laundries, require additional safety precautions. Detergent concentrates of this type therefore cannot be used, or can only be used with very heavy restrictions, in laundries.
It is mainly pulverulent detergents which are thus used in laundries. Since, in particular in large concerns with wide-scale automation, precise metering of such media is labor-intensive, the media are usually stored, and metered, in predissolved form as mother liquors, i.e. an aqueous concentrate is made up and is then supplied to the individual locations of use. However, the detergents which are usually used in laundries contain relatively high proportions of wash alkalis which are only soluble to a limited extent in cold water and, furthermore, result in salting-out effects. They cause phase separation, with the result that the organic components, in particular the nonionic surfactants and soaps, separate out and cream up. It is therefore necessary to work with relatively strong aqueous dilution, and the mother liquors additionally must be constantly mixed and circulated, in order to prevent individual components from separating out in the supply lines to the locations of use. Such processes thus require expensive large-volume mixing vessels, and the associated statics for mixers and feed devices, as well as a constant supply of energy for the temperature control and pumped circulation of the mother liquors.
A detergent which fulfills these requirements is described in EP 0 295 525 A1. This is a pasty detergent which requires special handling for the metering and mixing with water serving as a solvent. Such detergent pastes are transported and stored in large containers. It is proposed for these storage containers to be positioned in a dimensionally stable vessel arranged above the metering arrangement, and for the paste to be guided in a downwardly sloping manner. It is necessary at this point, prior to the insertion of the storage container, for the latter to be opened in the region of its outlet, which may result in the pasty product emerging from the storage container, and coming into contact with the operating staff, even during the operation of inserting the supply container. However, since such detergent pastes may constitute a hazardous substance, the situation where the pasty product emerges in an uncontrolled manner from the storage container is to be reliably avoided.